To overcome 100 Hz light flickering of fluorescent lamps working at 100 Hz alternating current, high-frequency eye care lamps employ a working frequency in the range of 40 kHz to 55 kHz. Inevitably, high-frequency ballasts can lead to electromagnetic radiation. If no action is taken, it is possible that high-frequency electromagnetic radiation is emitted to the outside world. Environmental-protection experts point out that excessive amounts of electromagnetic radiation can lead to palpitation, insomnia, memory degradation, and even reduction of immunity, as well as damage to the heart, the blood circulation system and the neural system. The public has come to the consensus that more protection can reduce the danger from electromagnetic radiation.
U.S. Pat. No. 3,774,024 discloses an illuminator grid adapted to be disposed beneath a source of light to intercept direct light rays travelling at less than a predetermined angle to the horizontal. The illuminator grid comprises a substantially horizontal array of substantially parallel and substantially equally spaced supports, a series of baffles suspending from said supports at substantially equally spaced positions along each support and in interspace positions on adjacent supports, and means connecting each baffle with the corresponding support to permit each baffle to be rotated on the corresponding support to an aligned position and to a position angular to the support, with baffles on alternating supports being oppositely inclined to the baffles on the supports there between. The width of said baffles is less than the center to center spacing of said baffles on the corresponding support and the width of said baffles is greater than the center to center distance between said supports.
The illuminator grid disclosed in U.S. Pat. No. 3,774,024 can only mask the glare of a light source from direct view, but cannot reduce or prevent the electromagnetic radiation from the light source.